Wiersma, William, author
Pearson/Allyn and Bacon, 2005
Buku Teks
Ross, Robert, author
N.Y. Barnes & Noble Books, 1974
Buku Teks
Blalock, Hubert M., author
Prentice-Hall, 1970
Buku Teks
Labovitz, Sanford, author
McGraw-Hill, 1971.
Buku Teks
Orenstein, Alan
The Falmer Press, 1978
Buku Teks